Welcome to PC, Bullrex. :D If you're interested in learning how to hack, then the Emulation Section of the forums is a good place for you to go! You'll learn so much about ROM Hacking which includes mapping, scripting, tiling, and much much much more. :D There are tons of tutorials for you to read, as well as the many tools you can use, and the advice you may want. :3
There's even a showcase where all the hacks were previously done here, and they have been done by members of this community. Check them out!
So, I hope you gather all the information you need to hack, and best of luck for it! :) See ya around! :)